The slapd.conf file consists of a series of global
configuration options that apply to slapd as a whole (including all
backends), followed by zero or more database backend definitions that
contain information specific to a backend instance. The configuration
options are case-insensitive; their value, on a case by case basis, may be
case-sensitive.

As many backend-specific sections as desired may be included.
Global options can be overridden in a backend (for options that appear more
than once, the last appearance in the slapd.conf file is used).

If a line begins with white space, it is considered a continuation
of the previous line. No physical line should be over 2000 bytes long.

Blank lines and comment lines beginning with a `#' character are
ignored. Note: continuation lines are unwrapped before comment processing is
applied.

Arguments on configuration lines are separated by white space. If
an argument contains white space, the argument should be enclosed in double
quotes. If an argument contains a double quote (`"') or a backslash
character (`\'), the character should be preceded by a backslash
character.

The specific configuration options available are discussed below
in the Global Configuration Options, General Backend Options, and General
Database Options. Backend-specific options are discussed in the
slapd-<backend>(5) manual pages. Refer to the "OpenLDAP
Administrator's Guide" for more details on the slapd configuration
file.

Options described in this section apply to all backends, unless specifically
overridden in a backend definition. Arguments that should be replaced by
actual text are shown in brackets <>.

access to <what> [ by <who> <access> <control>
]+

Grant access (specified by <access>) to a set of entries and/or
attributes (specified by <what>) by one or more requestors
(specified by <who>). If no access controls are present, the default
policy allows anyone and everyone to read anything but restricts updates
to rootdn. (e.g., "access to * by * read"). The rootdn can
always read and write EVERYTHING! See slapd.access(5) and the
"OpenLDAP's Administrator's Guide" for details.

allow <features>

Specify a set of features (separated by white space) to allow (default
none). bind_v2 allows acceptance of LDAPv2 bind requests. Note that
slapd(8) does not truly implement LDAPv2 (RFC 1777), now Historic
(RFC 3494). bind_anon_cred allows anonymous bind when credentials
are not empty (e.g. when DN is empty). bind_anon_dn allows
unauthenticated (anonymous) bind when DN is not empty. update_anon
allows unauthenticated (anonymous) update operations to be processed
(subject to access controls and other administrative limits).
proxy_authz_anon allows unauthenticated (anonymous) proxy
authorization control to be processed (subject to access controls,
authorization and other administrative limits).

argsfile <filename>

The (absolute) name of a file that will hold the slapd server's
command line (program name and options).

attributeoptions [option-name]...

Define tagging attribute options or option tag/range prefixes. Options
must not end with `-', prefixes must end with `-'. The `lang-' prefix is
predefined. If you use the attributeoptions directive, `lang-' will
no longer be defined and you must specify it explicitly if you want it
defined.

An attribute description with a tagging option is a subtype of
that attribute description without the option. Except for that, options
defined this way have no special semantics. Prefixes defined this way
work like the `lang-' options: They define a prefix for tagging options
starting with the prefix. That is, if you define the prefix `x-foo-',
you can use the option `x-foo-bar'. Furthermore, in a search or compare,
a prefix or range name (with a trailing `-') matches all options
starting with that name, as well as the option with the range name sans
the trailing `-'. That is, `x-foo-bar-' matches `x-foo-bar' and
`x-foo-bar-baz'.

RFC 4520 reserves options beginning with `x-' for private
experiments. Other options should be registered with IANA, see RFC 4520
section 3.5. OpenLDAP also has the `binary' option built in, but this is
a transfer option, not a tagging option.

Specify an attribute type using the LDAPv3 syntax defined
in RFC 4512. The slapd parser extends the RFC 4512 definition by allowing
string forms as well as numeric OIDs to be used for the attribute OID and
attribute syntax OID. (See the objectidentifier description.)

authid-rewrite<cmd> <args>

Used by the authentication framework to convert simple user names to an
LDAP DN used for authorization purposes. Its purpose is analogous to that
of authz-regexp (see below). The prefix authid- is followed
by a set of rules analogous to those described in slapo-rwm(5) for
data rewriting (replace the rwm- prefix with authid-).
authid-rewrite<cmd> and authz-regexp rules should not
be intermixed.

authz-policy <policy>

Used to specify which rules to use for Proxy Authorization. Proxy
authorization allows a client to authenticate to the server using one
user's credentials, but specify a different identity to use for
authorization and access control purposes. It essentially allows user A to
login as user B, using user A's password. The none flag disables
proxy authorization. This is the default setting. The from flag
will use rules in the authzFrom attribute of the authorization DN.
The to flag will use rules in the authzTo attribute of the
authentication DN. The any flag, an alias for the deprecated value
of both, will allow any of the above, whatever succeeds first
(checked in to, from sequence. The all flag requires
both authorizations to succeed.

The rules are mechanisms to specify which identities are
allowed to perform proxy authorization. The authzFrom attribute in an
entry specifies which other users are allowed to proxy login to this entry.
The authzTo attribute in an entry specifies which other users this user
can authorize as. Use of authzTo rules can be easily abused if users
are allowed to write arbitrary values to this attribute. In general the
authzTo attribute must be protected with ACLs such that only privileged
users can modify it. The value of authzFrom and authzTo
describes an identity or a set of identities; it can take five forms:

The first form is a valid LDAP URI where the
<host>:<port>, the <attrs> and the
<extensions> portions must be absent, so that the search occurs
locally on either authzFrom or authzTo. The second form is a
DN, with the optional style modifiers exact, onelevel,
children, and subtree for exact, onelevel, children and subtree
matches, which cause <pattern> to be normalized according to the
DN normalization rules, or the special regex style, which causes the
<pattern> to be treated as a POSIX (''extended'') regular
expression, as discussed in regex(7) and/or re_format(7). A
pattern of * means any non-anonymous DN. The third form is a SASL
id, with the optional fields <mech> and
<realm> that allow to specify a SASL mechanism, and
eventually a SASL realm, for those mechanisms that support one. The
need to allow the specification of a mechanism is still debated, and users are
strongly discouraged to rely on this possibility. The fourth form is a group
specification, consisting of the keyword group, optionally followed by
the specification of the group objectClass and member
attributeType. The group with DN <pattern> is searched
with base scope, and in case of match, the values of the member
attributeType are searched for the asserted DN. For backwards
compatibility, if no identity type is provided, i.e. only
<pattern> is present, an exact DN is assumed; as a
consequence, <pattern> is subjected to DN normalization. Since
the interpretation of authzFrom and authzTo can impact security,
users are strongly encouraged to explicitly set the type of identity
specification that is being used. A subset of these rules can be used as third
arg in the authz-regexp statement (see below); significantly, the
URI, provided it results in exactly one entry, and the
dn.exact:<dn> forms.

authz-regexp <match> <replace>

Used by the authentication framework to convert simple user names, such as
provided by SASL subsystem, or extracted from certificates in case of
cert-based SASL EXTERNAL, or provided within the RFC 4370 "proxied
authorization" control, to an LDAP DN used for authorization
purposes. Note that the resulting DN need not refer to an existing entry
to be considered valid. When an authorization request is received from the
SASL subsystem, the SASL USERNAME, REALM, and
MECHANISM are taken, when available, and combined into a name of
the form

UID=<username>[[,CN=<realm>],CN=<mechanism>],CN=auth

This name is then compared against the match POSIX (''extended'') regular
expression, and if the match is successful, the name is replaced with the
replace string. If there are wildcard strings in the match
regular expression that are enclosed in parenthesis, e.g.

UID=([^,]*),CN=.*

then the portion of the name that matched the wildcard will be stored in the
numbered placeholder variable $1. If there are other wildcard strings in
parenthesis, the matching strings will be in $2, $3, etc. up to $9. The
placeholders can then be used in the replace string, e.g.

UID=$1,OU=Accounts,DC=example,DC=com

The replaced name can be either a DN, i.e. a string prefixed by "dn:",
or an LDAP URI. If the latter, the server will use the URI to search its own
database(s) and, if the search returns exactly one entry, the name is replaced
by the DN of that entry. The LDAP URI must have no hostport, attrs, or
extensions components, but the filter is mandatory, e.g.

The protocol portion of the URI must be strictly ldap. Note that this
search is subject to access controls. Specifically, the authentication
identity must have "auth" access in the subject.

Multiple authz-regexp options can be given in the
configuration file to allow for multiple matching and replacement patterns.
The matching patterns are checked in the order they appear in the file,
stopping at the first successful match.

concurrency <integer>

Specify a desired level of concurrency. Provided to the underlying thread
system as a hint. The default is not to provide any hint.

conn_max_pending <integer>

Specify the maximum number of pending requests for an anonymous session.
If requests are submitted faster than the server can process them, they
will be queued up to this limit. If the limit is exceeded, the session is
closed. The default is 100.

conn_max_pending_auth <integer>

Specify the maximum number of pending requests for an authenticated
session. The default is 1000.

defaultsearchbase <dn>

Specify a default search base to use when client submits a non-base search
request with an empty base DN. Base scoped search requests with an empty
base DN are not affected.

disallow <features>

Specify a set of features (separated by white space) to disallow (default
none). bind_anon disables acceptance of anonymous bind requests.
Note that this setting does not prohibit anonymous directory access (See
"require authc"). bind_simple disables simple (bind)
authentication. tls_2_anon disables forcing session to anonymous
status (see also tls_authc) upon StartTLS operation receipt.
tls_authc disallows the StartTLS operation if authenticated (see
also tls_2_anon). proxy_authz_non_critical disables
acceptance of the proxied authorization control (RFC4370) when criticality
is FALSE. dontusecopy_non_critical disables acceptance of the
dontUseCopy control (a work in progress) when criticality is FALSE.

Specify an DIT Content Rule using the LDAPv3 syntax
defined in RFC 4512. The slapd parser extends the RFC 4512 definition by
allowing string forms as well as numeric OIDs to be used for the attribute OID
and attribute syntax OID. (See the objectidentifier description.)

gentlehup { on | off }

A SIGHUP signal will only cause a 'gentle' shutdown-attempt: Slapd
will stop listening for new connections, but will not close the
connections to the current clients. Future write operations return
unwilling-to-perform, though. Slapd terminates when all clients have
closed their connections (if they ever do), or - as before - if it
receives a SIGTERM signal. This can be useful if you wish to terminate the
server and start a new slapd server with another database,
without disrupting the currently active clients. The default is off. You
may wish to use idletimeout along with this option.

idletimeout <integer>

Specify the number of seconds to wait before forcibly closing an idle
client connection. A idletimeout of 0 disables this feature. The default
is 0. You may also want to set the writetimeout option.

include <filename>

Read additional configuration information from the given file before
continuing with the next line of the current file.

index_intlen <integer>

Specify the key length for ordered integer indices. The most significant
bytes of the binary integer will be used for index keys. The default value
is 4, which provides exact indexing for 31 bit values. A floating point
representation is used to index too large values.

index_substr_if_minlen <integer>

Specify the minimum length for subinitial and subfinal indices. An
attribute value must have at least this many characters in order to be
processed by the indexing functions. The default is 2.

index_substr_if_maxlen <integer>

Specify the maximum length for subinitial and subfinal indices. Only this
many characters of an attribute value will be processed by the indexing
functions; any excess characters are ignored. The default is 4.

index_substr_any_len <integer>

Specify the length used for subany indices. An attribute value must have
at least this many characters in order to be processed. Attribute values
longer than this length will be processed in segments of this length. The
default is 4. The subany index will also be used in subinitial and
subfinal index lookups when the filter string is longer than the
index_substr_if_maxlen value.

index_substr_any_step <integer>

Specify the steps used in subany index lookups. This value sets the offset
for the segments of a filter string that are processed for a subany index
lookup. The default is 2. For example, with the default values, a search
using this filter "cn=*abcdefgh*" would generate index lookups
for "abcd", "cdef", and "efgh".

Note: Indexing support depends on the particular backend in use.
Also, changing these settings will generally require deleting any indices
that depend on these parameters and recreating them with
slapindex(8).

Specify an LDAP syntax using the LDAPv3 syntax defined in
RFC 4512. The slapd parser extends the RFC 4512 definition by allowing string
forms as well as numeric OIDs to be used for the syntax OID. (See the
objectidentifier description.) The slapd parser also honors the
X-SUBST extension (an OpenLDAP-specific extension), which allows one to
use the ldapsyntax statement to define a non-implemented syntax along
with another syntax, the extension value substitute-syntax, as its
temporary replacement. The substitute-syntax must be defined. This
allows one to define attribute types that make use of non-implemented syntaxes
using the correct syntax OID. Unless X-SUBST is used, this
configuration statement would result in an error, since no handlers would be
associated to the resulting syntax structure.

listener-threads <integer>

Specify the number of threads to use for the connection manager. The
default is 1 and this is typically adequate for up to 16 CPU cores. The
value should be set to a power of 2.

localSSF <SSF>

Specifies the Security Strength Factor (SSF) to be given local LDAP
sessions, such as those to the ldapi:// listener. For a description of SSF
values, see sasl-secprops's minssf option description. The
default is 71.

logfile <filename>

Specify a file for recording debug log messages. By default these messages
only go to stderr and are not recorded anywhere else. Specifying a logfile
copies messages to both stderr and the logfile.

loglevel <integer> [...]

Specify the level at which debugging statements and operation statistics
should be syslogged (currently logged to the syslogd(8) LOG_LOCAL4
facility). They must be considered subsystems rather than increasingly
verbose log levels. Some messages with higher priority are logged
regardless of the configured loglevel as soon as any logging is
configured. Log levels are additive, and available levels are:

1

(0x1 trace) trace function calls

2

(0x2 packets) debug packet handling

4

(0x4 args) heavy trace debugging (function args)

8

(0x8 conns) connection management

16

(0x10 BER) print out packets sent and received

32

(0x20 filter) search filter processing

64

(0x40 config) configuration file processing

128

(0x80 ACL) access control list processing

256

(0x100 stats) connections, LDAP operations, results
(recommended)

512

(0x200 stats2) stats log entries sent

1024

(0x400 shell) print communication with shell backends

2048

(0x800 parse) entry parsing

16384

(0x4000 sync) LDAPSync replication

32768

(0x8000 none) only messages that get logged whatever log level is
set

The desired log level can be input as a single integer that combines the (ORed)
desired levels, both in decimal or in hexadecimal notation, as a list of
integers (that are ORed internally), or as a list of the names that are shown
between parentheses, such that

are equivalent. The keyword any can be used as a shortcut
to enable logging at all levels (equivalent to -1). The keyword none,
or the equivalent integer representation, causes those messages that are
logged regardless of the configured loglevel to be logged. In fact, if
loglevel is set to 0, no logging occurs, so at least the none level
is required to have high priority messages logged.

The loglevel defaults to stats. This level should usually
also be included when using other loglevels, to help analyze the logs.

moduleload <filename>

Specify the name of a dynamically loadable module to load. The filename
may be an absolute path name or a simple filename. Non-absolute names are
searched for in the directories specified by the modulepath option.
This option and the modulepath option are only usable if slapd was
compiled with --enable-modules.

modulepath <pathspec>

Specify a list of directories to search for loadable modules. Typically
the path is colon-separated but this depends on the operating system. The
default is /usr/lib/ldap, which is where the standard OpenLDAP install
will place its modules.

Specify an objectclass using the LDAPv3 syntax defined in
RFC 4512. The slapd parser extends the RFC 4512 definition by allowing string
forms as well as numeric OIDs to be used for the object class OID. (See the
objectidentifier description.) Object classes are
"STRUCTURAL" by default.

objectidentifier <name> { <oid> |
<name>[:<suffix>] }

Define a string name that equates to the given OID. The string can be used
in place of the numeric OID in objectclass and attribute definitions. The
name can also be used with a suffix of the form ":xx" in which
case the value "oid.xx" will be used.

password-hash <hash> [<hash>...]

This option configures one or more hashes to be used in generation of user
passwords stored in the userPassword attribute during processing of LDAP
Password Modify Extended Operations (RFC 3062). The <hash> must be
one of {SSHA}, {SHA}, {SMD5}, {MD5},
{CRYPT}, and {CLEARTEXT}. The default is {SSHA}.

{SHA} and {SSHA} use the SHA-1 algorithm (FIPS
160-1), the latter with a seed.

{MD5} and {SMD5} use the MD5 algorithm (RFC
1321), the latter with a seed.

This string needs to be in sprintf(3) format and may
include one (and only one) %s conversion. This conversion will be
substituted with a string of random characters from [A-Za-z0-9./]. For
example, "%.2s" provides a two character salt and
"$1$%.8s" tells some versions of crypt(3) to use an MD5
algorithm and provides 8 random characters of salt. The default is
"%s", which provides 31 characters of salt.

pidfile <filename>

The (absolute) name of a file that will hold the slapd server's
process ID (see getpid(2)).

referral <url>

Specify the referral to pass back when slapd(8) cannot find a local
database to handle a request. If specified multiple times, each url is
provided.

require <conditions>

Specify a set of conditions (separated by white space) to require (default
none). The directive may be specified globally and/or per-database;
databases inherit global conditions, so per-database specifications are
additive. bind requires bind operation prior to directory
operations. LDAPv3 requires session to be using LDAP version 3.
authc requires authentication prior to directory operations.
SASL requires SASL authentication prior to directory operations.
strong requires strong authentication prior to directory
operations. The strong keyword allows protected "simple"
authentication as well as SASL authentication. none may be used to
require no conditions (useful to clear out globally set conditions within
a particular database); it must occur first in the list of
conditions.

reverse-lookup on | off

Enable/disable client name unverified reverse lookup (default is
off if compiled with --enable-rlookups).

rootDSE <file>

Specify the name of an LDIF(5) file containing user defined attributes for
the root DSE. These attributes are returned in addition to the attributes
normally produced by slapd.

The root DSE is an entry with information about the server and
its capabilities, in operational attributes. It has the empty DN, and
can be read with e.g.: ldapsearch -x -b "" -s base
"+"
See RFC 4512 section 5.1 for details.

sasl-auxprops <plugin> [...]

Specify which auxprop plugins to use for authentication lookups. The
default is empty, which just uses slapd's internal support. Usually no
other auxprop plugins are needed.

sasl-host <fqdn>

Used to specify the fully qualified domain name used for SASL
processing.

Specify an integer ID from 0 to 4095 for this server (limited to 3
hexadecimal digits). The ID may also be specified as a hexadecimal ID by
prefixing the value with "0x". Non-zero IDs are required when
using multimaster replication and each master must have a unique non-zero
ID. Note that this requirement also applies to separate masters
contributing to a glued set of databases. If the URL is provided, this
directive may be specified multiple times, providing a complete list of
participating servers and their IDs. The fully qualified hostname of each
server should be used in the supplied URLs. The IDs are used in the
"replica id" field of all CSNs generated by the specified
server. The default value is zero, which is only valid for single master
replication. Example:

serverID 1

sizelimit {<integer>|unlimited}

sizelimit size[.{soft|hard|unchecked}]=<integer> [...]

Specify the maximum number of entries to return from a search operation.
The default size limit is 500. Use unlimited to specify no limits.
The second format allows a fine grain setting of the size limits. Extra
args can be added on the same line. See limits for an explanation
of the different flags.

Specify a list of multi-valued attributes whose values will always be
maintained in sorted order. Using this option will allow Modify, Compare,
and filter evaluations on these attributes to be performed more
efficiently. The resulting sort order depends on the attributes' syntax
and matching rules and may not correspond to lexical order or any other
recognizable order.

tcp-buffer [listener=<URL>] [{read|write}=]<size>

Specify the size of the TCP buffer. A global value for both read and write
TCP buffers related to any listener is defined, unless the listener is
explicitly specified, or either the read or write qualifiers are used. See
tcp(7) for details. Note that some OS-es implement automatic TCP
buffer tuning.

threads <integer>

Specify the maximum size of the primary thread pool. The default is 16;
the minimum value is 2.

timelimit {<integer>|unlimited}

timelimit time[.{soft|hard}]=<integer> [...]

Specify the maximum number of seconds (in real time) slapd will
spend answering a search request. The default time limit is 3600. Use
unlimited to specify no limits. The second format allows a fine
grain setting of the time limits. Extra args can be added on the same
line. See limits for an explanation of the different flags.

tool-threads <integer>

Specify the maximum number of threads to use in tool mode. This should not
be greater than the number of CPUs in the system. The default is 1.

writetimeout <integer>

Specify the number of seconds to wait before forcibly closing a connection
with an outstanding write. This allows recovery from various network hang
conditions. A writetimeout of 0 disables this feature. The default is
0.

If slapd is built with support for Transport Layer Security, there are
more options you can specify.

TLSCipherSuite <cipher-suite-spec>

Permits configuring what ciphers will be accepted and the preference
order. <cipher-suite-spec> should be a cipher specification for the
TLS library in use (OpenSSL, GnuTLS, or Mozilla NSS). Example:

OpenSSL:

TLSCipherSuite HIGH:MEDIUM:+SSLv2

GnuTLS:

TLSCiphersuite SECURE256:!AES-128-CBC

To check what ciphers a given spec selects in OpenSSL, use:

openssl ciphers -v <cipher-suite-spec>

With GnuTLS the available specs can be found in the manual page of
gnutls-cli(1) (see the description of the option
--priority).

In older versions of GnuTLS, where gnutls-cli does not support the
option --priority, you can obtain the — more limited — list of
ciphers by calling:

gnutls-cli -l

When using Mozilla NSS, the OpenSSL cipher suite specifications
are used and translated into the format used internally by Mozilla NSS.
There isn't an easy way to list the cipher suites from the command line. The
authoritative list is in the source code for Mozilla NSS in the file
sslinfo.c in the structure

static const SSLCipherSuiteInfo suiteInfo[]

TLSCACertificateFile <filename>

Specifies the file that contains certificates for all of the Certificate
Authorities that slapd will recognize. The certificate for the CA
that signed the server certificate must be included among these
certificates. If the signing CA was not a top-level (root) CA,
certificates for the entire sequence of CA's from the signing CA to the
top-level CA should be present. Multiple certificates are simply appended
to the file; the order is not significant.

TLSCACertificatePath <path>

Specifies the path of a directory that contains Certificate Authority
certificates in separate individual files. Usually only one of this or the
TLSCACertificateFile is used. This directive is not supported when using
GnuTLS.

When using Mozilla NSS, <path> may contain a Mozilla NSS
cert/key database. If <path> contains a Mozilla NSS cert/key
database and CA cert files, OpenLDAP will use the cert/key database and
will ignore the CA cert files.

TLSCertificateFile <filename>

Specifies the file that contains the slapd server certificate.

When using Mozilla NSS, if using a cert/key database
(specified with TLSCACertificatePath), TLSCertificateFile specifies the
name of the certificate to use:

TLSCertificateFile Server-Cert

If using a token other than the internal built in token, specify the token
name first, followed by a colon:

TLSCertificateFile my hardware device:Server-Cert

Use certutil -L to list the certificates by name:

certutil -d /path/to/certdbdir -L

TLSCertificateKeyFile <filename>

Specifies the file that contains the slapd server private key that
matches the certificate stored in the TLSCertificateFile file.
Currently, the private key must not be protected with a password, so it is
of critical importance that it is protected carefully.

When using Mozilla NSS, TLSCertificateKeyFile specifies the
name of a file that contains the password for the key for the
certificate specified with TLSCertificateFile. The modutil command can
be used to turn off password protection for the cert/key database. For
example, if TLSCACertificatePath specifes /etc/openldap/certdb as the
location of the cert/key database, use modutil to change the password to
the empty string:

modutil -dbdir /etc/openldap/certdb -changepw 'NSS Certificate DB'

You must have the old password, if any. Ignore the WARNING about the running
browser. Press 'Enter' for the new password.

TLSDHParamFile <filename>

This directive specifies the file that contains parameters for
Diffie-Hellman ephemeral key exchange. This is required in order to use a
DSA certificate on the server, or an RSA certificate missing the "key
encipherment" key usage. Note that setting this option may also
enable Anonymous Diffie-Hellman key exchanges in certain non-default
cipher suites. Anonymous key exchanges should generally be avoided since
they provide no actual client or server authentication and provide no
protection against man-in-the-middle attacks. You should append
"!ADH" to your cipher suites to ensure that these suites are not
used. When using Mozilla NSS these parameters are always generated
randomly so this directive is ignored.

TLSProtocolMin <major>[.<minor>]

Specifies minimum SSL/TLS protocol version that will be negotiated. If the
server doesn't support at least that version, the SSL handshake will fail.
To require TLS 1.x or higher, set this option to 3.(x+1), e.g.,

TLSProtocolMin 3.2

would require TLS 1.1. Specifying a minimum that is higher
than that supported by the OpenLDAP implementation will result in it
requiring the highest level that it does support. This directive is
ignored with GnuTLS.

TLSRandFile <filename>

Specifies the file to obtain random bits from when /dev/[u]random is not
available. Generally set to the name of the EGD/PRNGD socket. The
environment variable RANDFILE can also be used to specify the filename.
This directive is ignored with GnuTLS and Mozilla NSS.

TLSVerifyClient <level>

Specifies what checks to perform on client certificates in an incoming TLS
session, if any. The <level> can be specified as one of the
following keywords:

never

This is the default. slapd will not ask the client for a
certificate.

allow

The client certificate is requested. If no certificate is provided, the
session proceeds normally. If a bad certificate is provided, it will be
ignored and the session proceeds normally.

try

The client certificate is requested. If no certificate is provided, the
session proceeds normally. If a bad certificate is provided, the session
is immediately terminated.

demand | hard | true

These keywords are all equivalent, for compatibility reasons. The client
certificate is requested. If no certificate is provided, or a bad
certificate is provided, the session is immediately terminated.

Note that a valid client certificate is required in order to
use the SASL EXTERNAL authentication mechanism with a TLS session. As
such, a non-default TLSVerifyClient setting must be chosen to
enable SASL EXTERNAL authentication.

TLSCRLCheck <level>

Specifies if the Certificate Revocation List (CRL) of the CA should be
used to verify if the client certificates have not been revoked. This
requires TLSCACertificatePath parameter to be set. This directive
is ignored with GnuTLS and Mozilla NSS. <level> can be
specified as one of the following keywords:

none

No CRL checks are performed

peer

Check the CRL of the peer certificate

all

Check the CRL for a whole certificate chain

TLSCRLFile <filename>

Specifies a file containing a Certificate Revocation List to be used for
verifying that certificates have not been revoked. This directive is only
valid when using GnuTLS and Mozilla NSS.

Options in this section only apply to the configuration file section for the
specified backend. They are supported by every type of backend.

backend <databasetype>

Mark the beginning of a backend definition. <databasetype> should be
one of bdb, config, dnssrv, hdb, ldap,
ldif, mdb, meta, monitor, null,
passwd, perl, relay, shell, or sql,
depending on which backend will serve the database.

Options in this section only apply to the configuration file section for the
database in which they are defined. They are supported by every type of
backend. Note that the database and at least one suffix option
are mandatory for each database.

database <databasetype>

Mark the beginning of a new database instance definition.
<databasetype> should be one of bdb, config,
dnssrv, hdb, ldap, ldif, mdb,
meta, monitor, null, passwd, perl,
relay, shell, or sql, depending on which backend will
serve the database.

LDAP operations, even subtree searches, normally access only
one database. That can be changed by gluing databases together with the
subordinate keyword. Access controls and some overlays can also
involve multiple databases.

add_content_acl on | off

Controls whether Add operations will perform ACL checks on the content of
the entry being added. This check is off by default. See the
slapd.access(5) manual page for more details on ACL requirements
for Add operations.

extra_attrs <attrlist>

Lists what attributes need to be added to search requests. Local storage
backends return the entire entry to the frontend. The frontend takes care
of only returning the requested attributes that are allowed by ACLs.
However, features like access checking and so may need specific attributes
that are not automatically returned by remote storage backends, like proxy
backends and so on. <attrlist> is a list of attributes that
are needed for internal purposes and thus always need to be collected,
even when not explicitly requested by clients.

hidden on | off

Controls whether the database will be used to answer queries. A database
that is hidden will never be selected to answer any queries, and any
suffix configured on the database will be ignored in checks for conflicts
with other databases. By default, hidden is off.

lastmod on | off

Controls whether slapd will automatically maintain the
modifiersName, modifyTimestamp, creatorsName, and createTimestamp
attributes for entries. It also controls the entryCSN and entryUUID
attributes, which are needed by the syncrepl provider. By default, lastmod
is on.

limits <selector> <limit> [<limit> [...]]

Specify time and size limits based on the operation's initiator or base
DN. The argument <selector> can be any of

DN type self is the default and means the bound user, while this
means the base DN of the operation. The term anonymous matches all
unauthenticated clients. The term users matches all authenticated
clients; otherwise an exact dn pattern is assumed unless otherwise
specified by qualifying the (optional) key string dn with exact
or base (which are synonyms), to require an exact match; with
onelevel, to require exactly one level of depth match; with
subtree, to allow any level of depth match, including the exact match;
with children, to allow any level of depth match, not including the
exact match; regex explicitly requires the (default) match based on
POSIX (''extended'') regular expression pattern. Finally, anonymous
matches unbound operations; the pattern field is ignored. The same
behavior is obtained by using the anonymous form of the
<selector> clause. The term group, with the optional
objectClass oc and attributeType at fields, followed by
pattern, sets the limits for any DN listed in the values of the
at attribute (default member) of the oc group objectClass
(default groupOfNames) whose DN exactly matches pattern.

The currently supported limits are size and
time.

The syntax for time limits is
time[.{soft|hard}]=<integer>, where integer is the
number of seconds slapd will spend answering a search request. If no time
limit is explicitly requested by the client, the soft limit is used;
if the requested time limit exceeds the hard limit, the value of the
limit is used instead. If the hard limit is set to the keyword
soft, the soft limit is used in either case; if it is set to the
keyword unlimited, no hard limit is enforced. Explicit requests for
time limits smaller or equal to the hard limit are honored. If no
limit specifier is set, the value is assigned to the soft limit, and
the hard limit is set to soft, to preserve the original
behavior.

The syntax for size limits is
size[.{soft|hard|unchecked}]=<integer>, where integer is
the maximum number of entries slapd will return answering a search request.
If no size limit is explicitly requested by the client, the soft
limit is used; if the requested size limit exceeds the hard limit,
the value of the limit is used instead. If the hard limit is set to
the keyword soft, the soft limit is used in either case; if it is set
to the keyword unlimited, no hard limit is enforced. Explicit
requests for size limits smaller or equal to the hard limit are
honored. The unchecked specifier sets a limit on the number of
candidates a search request is allowed to examine. The rationale behind it
is that searches for non-properly indexed attributes may result in large
sets of candidates, which must be examined by slapd(8) to determine
whether they match the search filter or not. The unchecked limit
provides a means to drop such operations before they are even started. If
the selected candidates exceed the unchecked limit, the search will
abort with Unwilling to perform. If it is set to the keyword
unlimited, no limit is applied (the default). If it is set to
disabled, the search is not even performed; this can be used to
disallow searches for a specific set of users. If no limit specifier is set,
the value is assigned to the soft limit, and the hard limit is
set to soft, to preserve the original behavior.

In case of no match, the global limits are used. The default
values are the same as for sizelimit and timelimit; no limit
is set on unchecked.

If pagedResults control is requested, the hard size
limit is used by default, because the request of a specific page size is
considered an explicit request for a limitation on the number of entries to
be returned. However, the size limit applies to the total count of entries
returned within the search, and not to a single page. Additional size limits
may be enforced; the syntax is
size.pr={<integer>|noEstimate|unlimited}, where integer
is the max page size if no explicit limit is set; the keyword
noEstimate inhibits the server from returning an estimate of the
total number of entries that might be returned (note: the current
implementation does not return any estimate). The keyword unlimited
indicates that no limit is applied to the pagedResults control page size.
The syntax size.prtotal={<integer>|unlimited|disabled} allows
one to set a limit on the total number of entries that the pagedResults
control will return. By default it is set to the hard limit. When
set, integer is the max number of entries that the whole search with
pagedResults control can return. Use unlimited to allow unlimited
number of entries to be returned, e.g. to allow the use of the pagedResults
control as a means to circumvent size limitations on regular searches; the
keyword disabled disables the control, i.e. no paged results can be
returned. Note that the total number of entries returned when the
pagedResults control is requested cannot exceed the hard size limit
of regular searches unless extended by the prtotal switch.

The limits statement is typically used to let an unlimited
number of entries be returned by searches performed with the identity used
by the consumer for synchronization purposes by means of the RFC 4533 LDAP
Content Synchronization protocol (see syncrepl for details).

maxderefdepth <depth>

Specifies the maximum number of aliases to dereference when trying to
resolve an entry, used to avoid infinite alias loops. The default is
15.

mirrormode on | off

This option puts a replica database into "mirror" mode. Update
operations will be accepted from any user, not just the updatedn. The
database must already be configured as a syncrepl consumer before this
keyword may be set. This mode also requires a serverID (see above)
to be configured. By default, mirrormode is off.

monitoring on | off

This option enables database-specific monitoring in the entry related to
the current database in the "cn=Databases,cn=Monitor" subtree of
the monitor database, if the monitor database is enabled. Currently, only
the BDB and the HDB databases provide database-specific monitoring. The
default depends on the backend type.

overlay <overlay-name>

Add the specified overlay to this database. An overlay is a piece of code
that intercepts database operations in order to extend or change them.
Overlays are pushed onto a stack over the database, and so they will
execute in the reverse of the order in which they were configured and the
database itself will receive control last of all. See the
slapd.overlays(5) manual page for an overview of the available
overlays. Note that all of the database's regular settings should be
configured before any overlay settings.

readonly on | off

This option puts the database into "read-only" mode. Any
attempts to modify the database will return an "unwilling to
perform" error. By default, readonly is off.

restrict <oplist>

Specify a whitespace separated list of operations that are restricted. If
defined inside a database specification, restrictions apply only to that
database, otherwise they are global. Operations can be any of add,
bind, compare, delete, extended[=<OID>],
modify, rename, search, or the special
pseudo-operations read and write, which respectively
summarize read and write operations. The use of restrict write is
equivalent to readonly on (see above). The extended keyword
allows one to indicate the OID of the specific operation to be
restricted.

rootdn <dn>

Specify the distinguished name that is not subject to access control or
administrative limit restrictions for operations on this database. This DN
may or may not be associated with an entry. An empty root DN (the default)
specifies no root access is to be granted. It is recommended that the
rootdn only be specified when needed (such as when initially populating a
database). If the rootdn is within a namingContext (suffix) of the
database, a simple bind password may also be provided using the
rootpw directive. Many optional features, including syncrepl,
require the rootdn to be defined for the database.

rootpw <password>

Specify a password (or hash of the password) for the rootdn. The password
can only be set if the rootdn is within the namingContext (suffix) of the
database. This option accepts all RFC 2307 userPassword formats known to
the server (see password-hash description) as well as cleartext.
slappasswd(8) may be used to generate a hash of a password.
Cleartext and {CRYPT} passwords are not recommended. If empty (the
default), authentication of the root DN is by other means (e.g. SASL). Use
of SASL is encouraged.

suffix <dn suffix>

Specify the DN suffix of queries that will be passed to this backend
database. Multiple suffix lines can be given and at least one is required
for each database definition.

If the suffix of one database is "inside" that of
another, the database with the inner suffix must come first in the
configuration file. You may also want to glue such databases together
with the subordinate keyword.

subordinate [advertise]

Specify that the current backend database is a subordinate of another
backend database. A subordinate database may have only one suffix. This
option may be used to glue multiple databases into a single namingContext.
If the suffix of the current database is within the namingContext of a
superior database, searches against the superior database will be
propagated to the subordinate as well. All of the databases associated
with a single namingContext should have identical rootdns. Behavior of
other LDAP operations is unaffected by this setting. In particular, it is
not possible to use moddn to move an entry from one subordinate to another
subordinate within the namingContext.

If the optional advertise flag is supplied, the naming
context of this database is advertised in the root DSE. The default is
to hide this database context, so that only the superior context is
visible.

If the slap tools slapcat(8), slapadd(8), or
slapindex(8) are used on the superior database, any glued
subordinates that support these tools are opened as well.

Databases that are glued together should usually be configured
with the same indices (assuming they support indexing), even for
attributes that only exist in some of these databases. In general, all
of the glued databases should be configured as similarly as possible,
since the intent is to provide the appearance of a single directory.

Note that the subordinate functionality is implemented
internally by the glue overlay and as such its behavior will
interact with other overlays in use. By default, the glue overlay is
automatically configured as the last overlay on the superior backend.
Its position on the backend can be explicitly configured by setting an
overlay glue directive at the desired position. This explicit
configuration is necessary e.g. when using the syncprov overlay,
which needs to follow glue in order to work over all of the glued
databases. E.g.

Specify the current database as a replica which is kept
up-to-date with the master content by establishing the current slapd(8)
as a replication consumer site running a syncrepl replication engine.
The replica content is kept synchronized to the master content using the LDAP
Content Synchronization protocol. Refer to the "OpenLDAP Administrator's
Guide" for detailed information on setting up a replicated slapd
directory service using the syncrepl replication engine.

rid identifies the current syncrepl directive within
the replication consumer site. It is a non-negative integer not greater than
999 (limited to three decimal digits).

provider specifies the replication provider site containing
the master content as an LDAP URI. If <port> is not given, the
standard LDAP port number (389 or 636) is used.

The content of the syncrepl replica is defined using a
search specification as its result set. The consumer slapd will send
search requests to the provider slapd according to the search
specification. The search specification includes searchbase,
scope, filter, attrs, attrsonly,
sizelimit, and timelimit parameters as in the normal search
specification. The scope defaults to sub, the filter
defaults to (objectclass=*), while there is no default
searchbase. The attrs list defaults to "*,+"
to return all user and operational attributes, and attrsonly is unset
by default. The sizelimit and timelimit only accept
"unlimited" and positive integers, and both default to
"unlimited". The sizelimit and timelimit parameters
define a consumer requested limitation on the number of entries that can be
returned by the LDAP Content Synchronization operation; as such, it is
intended to implement partial replication based on the size of the
replicated database and on the time required by the synchronization. Note,
however, that any provider-side limits for the replication identity will be
enforced by the provider regardless of the limits requested by the LDAP
Content Synchronization operation, much like for any other search operation.
exattrs option may also be used to specify attributes that should be
omitted from incoming entries. The scope defaults to sub, the
filter defaults to (objectclass=*), and there is no default
searchbase. The attrs list defaults to "*,+"
to return all user and operational attributes, and attrsonly and
exattrs are unset by default. The sizelimit and
timelimit only accept "unlimited" and positive integers,
and both default to "unlimited". Note, however, that any
provider-side limits for the replication identity will be enforced by the
provider regardless of the limits requested by the LDAP Content
Synchronization operation, much like for any other search operation.

The LDAP Content Synchronization protocol has two operation types.
In the refreshOnly operation, the next synchronization search
operation is periodically rescheduled at an interval time (specified by
interval parameter; 1 day by default) after each synchronization
operation finishes. In the refreshAndPersist operation, a
synchronization search remains persistent in the provider slapd. Further
updates to the master replica will generate searchResultEntry to the
consumer slapd as the search responses to the persistent synchronization
search. If the initial search fails due to an error, the next
synchronization search operation is periodically rescheduled at an interval
time (specified by interval parameter; 1 day by default)

If an error occurs during replication, the consumer will attempt
to reconnect according to the retry parameter which is a list of the
<retry interval> and <# of retries> pairs. For example,
retry="60 10 300 3" lets the consumer retry every 60 seconds for
the first 10 times and then retry every 300 seconds for the next 3 times
before stop retrying. The `+' in <# of retries> means indefinite
number of retries until success. If no retry was specified, by
default syncrepl retries every hour forever.

The schema checking can be enforced at the LDAP Sync consumer site
by turning on the schemachecking parameter. The default is
off. Schema checking on means that replicated entries must
have a structural objectClass, must obey to objectClass requirements in
terms of required/allowed attributes, and that naming attributes and
distinguished values must be present. As a consequence, schema checking
should be off when partial replication is used.

The network-timeout parameter sets how long the consumer
will wait to establish a network connection to the provider. Once a
connection is established, the timeout parameter determines how long
the consumer will wait for the initial Bind request to complete. The
defaults for these parameters come from ldap.conf(5).

A bindmethod of simple requires the options
binddn and credentials and should only be used when adequate
security services (e.g. TLS or IPSEC) are in place. REMEMBER: simple bind
credentials must be in cleartext! A bindmethod of sasl
requires the option saslmech. Depending on the mechanism, an
authentication identity and/or credentials can be specified using
authcid and credentials. The authzid parameter may be
used to specify an authorization identity. Specific security properties (as
with the sasl-secprops keyword above) for a SASL bind can be set with
the secprops option. A non default SASL realm can be set with the
realm option. The identity used for synchronization by the consumer
should be allowed to receive an unlimited number of entries in response to a
search request. The provider, other than allow authentication of the
syncrepl identity, should grant that identity appropriate access privileges
to the data that is being replicated (access directive), and
appropriate time and size limits. This can be accomplished by either
allowing unlimited sizelimit and timelimit, or by setting an
appropriate limits statement in the consumer's configuration (see
sizelimit and limits for details).

The keepalive parameter sets the values of idle,
probes, and interval used to check whether a socket is alive;
idle is the number of seconds a connection needs to remain idle
before TCP starts sending keepalive probes; probes is the maximum
number of keepalive probes TCP should send before dropping the connection;
interval is interval in seconds between individual keepalive probes.
Only some systems support the customization of these values; the
keepalive parameter is ignored otherwise, and system-wide settings
are used.

The starttls parameter specifies use of the StartTLS
extended operation to establish a TLS session before Binding to the
provider. If the critical argument is supplied, the session will be
aborted if the StartTLS request fails. Otherwise the syncrepl session
continues without TLS. The tls_reqcert setting defaults to
"demand" and the other TLS settings default to the same as the
main slapd TLS settings.

The suffixmassage parameter allows the consumer to pull
entries from a remote directory whose DN suffix differs from the local
directory. The portion of the remote entries' DNs that matches the
searchbase will be replaced with the suffixmassage DN.

Rather than replicating whole entries, the consumer can query logs
of data modifications. This mode of operation is referred to as deltasyncrepl. In addition to the above parameters, the logbase and
logfilter parameters must be set appropriately for the log that will
be used. The syncdata parameter must be set to either
"accesslog" if the log conforms to the slapo-accesslog(5)
log format, or "changelog" if the log conforms to the obsolete
changelog format. If the syncdata parameter is omitted or set
to "default" then the log parameters are ignored.

updatedn <dn>

This option is only applicable in a slave database. It specifies the DN
permitted to update (subject to access controls) the replica. It is only
needed in certain push-mode replication scenarios. Generally, this DN
should not be the same as the rootdn used at the
master.

updateref <url>

Specify the referral to pass back when slapd(8) is asked to modify
a replicated local database. If specified multiple times, each url is
provided.